Dry bubble disease (Verticillium)

Dry bubble disease may cause a lot of problems because the spores spread quickly. It’s essential to identify and remove the first affected mushrooms to prevent an outbreak of the disease throughout your entire nursery. So how do you remove the first infected mushrooms?

Spread by spores

Dry bubble disease is spread by spores. The spores are sticky and are spread by any carrier to which they may adhere, such as people, flies, dust, water, etc.

Preventing the spread

The best way of preventing the spread of spores is by covering an infected mushroom and removing it. Wet a tissue with a disinfectant such as alcohol or methylated spirits. The spores will stick to a wet tissue. Carefully and slowly place the wet tissue over the infected mushroom without causing any turbulence, which would make the spores fly away. When you have covered the mushroom with the tissue, cover your hand with a plastic bag and pick up the mushroom along with a good amount of the surrounding casing soil. Turn the bag containing the infected mushroom and the casing soil inside out and seal it. Leave the bag containing the infected mushroom in the growing room and dispose of it after you have steamed the growing room.

There are other methods you could use, for
example with a plastic bottle. Cut off the bottle’s base, place the bottle over
the infected mushroom and fill it with salt.

Whichever method you use, make sure you
don’t spread the spores. A single drop of water on an infected mushroom would
spread billions of spores over a distance of more than one metre from the
mushroom. A few days later you would then see lots of mushrooms showing the
first signs of dry bubble disease around that first mushroom.

Regularly check the area from which you
have removed the infected mushroom during the next few days to see whether the
disease reappears.

More information on how to control dry bubble disease can be found on pages 114-116 of the Mushroom Signals book.

Mark den Ouden|Mushroom Blog

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